Electrinocellia
Encyclopedia
Electrinocellia is an extinct monotypic
genus
of Snakefly
in the family Inocelliidae
containing the single species Electrinocellia peculiaris and known from Eocene
aged Baltic amber
.
, a single dark brown male specimen, deposited in the Harvard University
Museum of Comparative Zoology
as specimen number 51. The specimen was first studied and described by the prolific paleoentomologist
Dr. Frank M. Carpenter
, while he was curator of the Harvard paleoentomological collections.The genus was named from the Latin electrum meaning "amber" and Inocellia, the type genus for Inocelliidae. The species name peculiaris is a reference to the enigmatic nature of the species when first studied.
When first described the species was placed in Inocellia as Inocellia peculiaris. In his type description of the species, Dr. Carpenter noted a number of odd features which do not conform well with extant Inocellia species. The specimen possesses antennae placed far back on the head, lacks ocelli, a pterostigma
without crossvein, all structures found in Inocellia. The genitalia are also very close in structure to Inocellia. However the species also has distinct vein structures, and an overall head shape which is less quadrate, features not found in Inocellia. The size of the specimen is also notably smaller than other species of Inocellia, the fore wing being only 6 millimetre (0.236220472440945 in) long and 1.8 millimetre (0.0708661417322835 in) wide. Dr. Carpenter therefore placed the species in Inocellia and noted his reservations regarding the placement but did not feel that the differences were enough to warrant creation of a new genus.
Though they did not move the species to a new genus, Horst Aspöck, Ulrike Aspöck and Hubert Rausch in the 1991 work Die Raphidiopteren der Erde also noted the very odd nature of the species and questioned its placement in Inocellia. Dr Michael S. Engel
restudied the type specimen and moved the species in a 1995 paper published in the entomology journal Psyche
, 39 years after the type description was published in the same journal. Dr. Engel, noting the oddities moved the species to a new genus Electrinocellia which he in turn placed in the monotypic subfamily Electrinocellinae. This subfamily is a sister taxon
to the rest of the genera in Inocelliidae, which are in the subfamily Inocelliidinae.
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Snakefly
Snakefly
Snakeflies are a group of insects in the order Raphidioptera, consisting of about 210 extant species. Together with the Megaloptera they were formerly placed within the Neuroptera, but now these two are generally regarded as separate orders....
in the family Inocelliidae
Inocelliidae
Inocelliidae is a small family of snakeflies containing 8 genera of which one is known only from fossils. They are commonly known as inocelliid snakeflies...
containing the single species Electrinocellia peculiaris and known from Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
aged Baltic amber
Baltic amber
The Baltic region is home to the largest known deposit of amber, called Baltic amber or succinite, with about 80% of the world's known amber found there. It dates from 44 million years ago...
.
History and classification
The genus is known from only the holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
, a single dark brown male specimen, deposited in the Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
Museum of Comparative Zoology
Museum of Comparative Zoology
The Museum of Comparative Zoology, full name "The Louis Agassiz Museum of Comparative Zoology", often abbreviated simply to "MCZ", is a zoology museum located on the grounds of Harvard University in Cambridge, Massachusetts. It is one of three museums which collectively comprise the Harvard Museum...
as specimen number 51. The specimen was first studied and described by the prolific paleoentomologist
Entomology
Entomology is the scientific study of insects, a branch of arthropodology...
Dr. Frank M. Carpenter
Frank M. Carpenter
Frank M. Carpenter received his PhD from Harvard University, and was curator of fossil insects at the Harvard Museum of Comparative Zoology for 60 years. He studied the Permian fossil insects of Elmo, Kansas, and compared the North American fossil insect fauna with Paleozoic taxa known from...
, while he was curator of the Harvard paleoentomological collections.The genus was named from the Latin electrum meaning "amber" and Inocellia, the type genus for Inocelliidae. The species name peculiaris is a reference to the enigmatic nature of the species when first studied.
When first described the species was placed in Inocellia as Inocellia peculiaris. In his type description of the species, Dr. Carpenter noted a number of odd features which do not conform well with extant Inocellia species. The specimen possesses antennae placed far back on the head, lacks ocelli, a pterostigma
Pterostigma
The pterostigma is a cell in the outer wing of insects which is often thickened or coloured and so stands out from other cells. It is particularly noticeable in dragonflies, but present also in other insect groups, such as snakeflies, hymenopterans and megalopterans.The purpose of the pterostigma,...
without crossvein, all structures found in Inocellia. The genitalia are also very close in structure to Inocellia. However the species also has distinct vein structures, and an overall head shape which is less quadrate, features not found in Inocellia. The size of the specimen is also notably smaller than other species of Inocellia, the fore wing being only 6 millimetre (0.236220472440945 in) long and 1.8 millimetre (0.0708661417322835 in) wide. Dr. Carpenter therefore placed the species in Inocellia and noted his reservations regarding the placement but did not feel that the differences were enough to warrant creation of a new genus.
Though they did not move the species to a new genus, Horst Aspöck, Ulrike Aspöck and Hubert Rausch in the 1991 work Die Raphidiopteren der Erde also noted the very odd nature of the species and questioned its placement in Inocellia. Dr Michael S. Engel
Michael S. Engel
Michael S. Engel is an American paleontologist and entomologist. He has undertaken field work in Central Asia, Asia Minor, and the Western Hemisphere, and published more than 300 papers in scientific journals. He was trained at the University of Kansas where in 1993 he received a B.S. in Cellular...
restudied the type specimen and moved the species in a 1995 paper published in the entomology journal Psyche
Psyche (entomological journal)
Psyche is a scientific journal of entomology which was established in 1874 by the Cambridge Entomological Club as a "journal for the publication of biological contributions upon Arthropoda from any competent person"....
, 39 years after the type description was published in the same journal. Dr. Engel, noting the oddities moved the species to a new genus Electrinocellia which he in turn placed in the monotypic subfamily Electrinocellinae. This subfamily is a sister taxon
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
to the rest of the genera in Inocelliidae, which are in the subfamily Inocelliidinae.